DC-DC converter

ABSTRACT

The present embodiment relates to a DC-DC converter including: a housing; a plurality of electronic components disposed inside the housing; and a flow path disposed on a lower plate of the housing. The flow path includes an expanding portion. The horizontal width of the expanding portion is greater than the horizontal width of a flow path on the front end of the expanding portion, and the vertical width of the expanding portion is less than the vertical width of the flow path on the front end of the expanding portion. The differential between the part wherein the surface area of the vertical cross section of the flow path is the biggest and the part wherein the surface area of the vertical cross section of the flow path is the smallest is 10% or less.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.16/343,963 filed on Apr. 22, 2019, which is the National Phase ofPCT/KR2017/013090 filed on Nov. 17, 2017, which claims priority under 35U.S.C. § 119(a) to Patent Application Nos. 10-2016-0153088;10-2016-0180862; 10-2017-0148773; 10-2017-0152770; and 10-2017-0152771filed in the Republic of Korea on Nov. 17, 2016; Dec. 28, 2016; Nov. 9,2017; Nov. 16, 2017; and Nov. 16, 2017 respectively, all of which arehereby expressly incorporated by reference into the present application.

TECHNICAL FIELD

The present exemplary embodiment relates to a DC-DC converter.

BACKGROUND ART

The following description provides background information for thepresent embodiment and does not describe the prior art.

With the emergence of environmentally friendly vehicles using electricpower, it is required to reduce the weight and size of electric partsfor vehicles. A DC-DC (direct current to direct current) converter for avehicle is a device for controlling a DC voltage in a vehicle.

Particularly, in an electric vehicle, it plays the role of changingvoltage of a current generated in a motor so as to supply to a battery.In addition, when the electric vehicle is driving down an inclined road,the motor serves as a generator to charge the battery. In this case, thevoltage of the electric current generated by the motor is changed andsupplied to the battery.

Various electronic components are disposed in the DC-DC converter. It isnecessary to improve the cooling efficiency of a heating module forvarious reasons such as weight reduction of the DC-DC converter andimplementation of a compact structure.

On the other hand, the main configuration of the DC-DC convertercomprises a primary coil through which a current supplied from theoutside flows, a secondary coil which generates an induced current by acurrent flowing through the primary coil, and an inductor coilelectrically connected to the secondary coil and controlling thefrequency of a converted current. More specifically, the conversion ofthe current is accomplished through the electromagnetic interactionbetween the primary coil and secondary coil, and the converted currentis filtered through the inductor coil to filter the noise frequency andthen supplied to an external device via a bus bar. Generally, each ofthe secondary coil, the inductor coil, and the bus bar is separatelymanufactured as a single member through complicated processes such assheet press cutting, bolt hole punching, bending, forging, and the like,and later, they are coupled together with bolts, thereby being connectedelectrically. However, such a manufacturing process is too complicated,and further, during bolt-coupling, there is a problem in that thecoupling may be incomplete or a gap may be induced due to the warping ofthe material and the like. In particular, the gaps between the secondarycoil and the inductor coil, and the inductor coil and the bus bar causeproblems such as heat generation due to an increase in contactresistance as well as deterioration in electrical characteristics. Inaddition, since the secondary coil, the inductor coil, and the bus barare independently manufactured as a single member, there is a problem inthat the size and the weight of the DC-DC converter increase.

Meanwhile, the DC-DC converter may comprise a housing and a coolingplate disposed in the housing in the form of a horizontal partition soas to divide the housing into a first region and a second region. Inaddition, a cooling flow path is formed in the first region throughwhich cooling water flows, and electronic components (for example,boards for mounting various devices) are disposed in the second region.That is, the first region performs a function of cooling the electroniccomponent part with the cooling part, and the second region performs anelectronic control function of converting the voltage of the externalpower source for the electronic component part. Recently, researches arebeing carried out to reduce the size of the DC-DC converter and toimprove the cooling efficiency of the electronic component parts due tothe request of the vehicle manufacturers and the emergence of smart andhybrid automobiles.

DETAILED DESCRIPTION OF THE INVENTION Technical Subject

In the first embodiment, a DC-DC converter which improves coolingefficiency of a heating module is provided.

In the second embodiment, a DC-DC converter which simplifies themanufacturing processes and improves the conversion efficiency byintegrally forming a secondary coil, an inductor coil, and a bus bar,and comprising a coil module having a compact structure is provided.

In the third embodiment, a DC-DC converter having a reduced size and ahigh cooling efficiency is provided.

Technical Solution

A DC-DC converter of the first embodiment comprises: a housing; aplurality of electronic components disposed inside the housing; and aflow path disposed on a lower plate of the housing, wherein the flowpath comprises an expanding portion, and the horizontal width of theexpanding portion is greater than the horizontal width of a flow path onthe front end of the expanding portion, and the vertical width of theexpanding portion is less than the vertical width of the flow path onthe front end of the expanding portion, and the differential between theportion wherein the surface area of the vertical cross section of theflow path is the biggest and the portion wherein the surface area of thevertical cross section of the flow path is the smallest is 10% or less.

The plurality of electronic components may comprise a plurality ofheating elements, and one of the plurality of heating elements may bedisposed corresponding to the expanding portion.

The one of the plurality of heating elements may be overlapping with theexpanding portion along the vertical direction.

The maximum horizontal cross section of the expanding portion, the areabeing overlapped in the vertical direction with the one of the pluralityof heating elements, may be greater than 30%.

The maximum horizontal cross section of the expanding portion may begreater than 90% of the one of the plurality of heating elements.

A protruding part downwardly protruded towards the lower plate may belocated.

The height of the protruding part may be increasing and then decreasingalong the direction of the movement of the cooling material.

The area of the vertical cross section of the protruding part has theshape of a rectangle, and the area of the vertical cross section of theprotruding part may be increasing and then decreasing along thedirection of the movement of the cooling material.

The area of the horizontal cross section of the protruding part has ashape wherein the curvature is convexly formed towards the lower plate,and the area of the horizontal cross section of the protruding part maybe decreasing as it travels from the center of the horizontal width ofthe flow path towards the edge.

The area of the vertical cross section of the flow path may be equalalong the movement direction of the cooling material.

The plurality of electronic components may comprise a plurality ofheating elements, and the plurality of heating elements may comprise adiode module, and the diode module may be disposed to correspond to theexpanding portion in a vertical direction.

The flow path further comprises an inlet portion through which thecooling material sequentially moves, a first curved portion, a secondcurved portion, and a discharge portion, the inlet portion and thedischarge portion being spaced apart in the horizontal width directionof the flow path, and the first curved portion and the expanding portionmay be spaced apart in the horizontal width direction of the flow path.

The inlet portion and the discharge portion may be disposed parallel toeach other, and the first curved portion may be formed in a way that thecurvature is convexly formed in the direction wherein the expandingportion is located, and the second curved portion may be formed in a waythat curvature is convexly formed in the direction opposite to thedirection where a space between the first curved portion and theexpanding portion is located.

The plurality of electronic components comprises a heating element,wherein the heating element comprises an inductor, a transformer, aZero-Voltage-Switching (ZVS) inductor, a switching module, and a diodemodule; the inductor is disposed so as to correspond to a verticaldirection with respect to the inlet portion; the transformer is arrangedto correspond to the first curved portion in the vertical direction; theZVS (Zero-Voltage-Switching) inductor is disposed so as to be verticallyaligned with the front end of the second curved portion; the switchingmodule is disposed to correspond to the second curved portion in thevertical direction; and the diode module may be disposed to correspondto the expanding portion in the vertical direction.

The inductor continuously controls the current flow; the transformercontrols the power by changing the voltage of the current; the ZVS(Zero-Voltage-Switching) inductor controls the light load; the switchingmodule controls ON/OFF of the current; and the diode module can controlthe direction of the current.

The housing comprises a side plate extending upward from the lower plateand an upper cover disposed on the side plate, and the plurality ofelectronic components can be disposed in a space formed by the lowerplate, the side plate, and the top cover.

It may comprise: a connector electrically connected to an externalelectronic device; an inlet through which the cooling material flowsinto the flow path; and an outlet through which the cooling material isdischarged from the flow path, wherein the connector is disposed on theside plate, the inlet and the outlet may be located on the opposite sideof the connector and disposed on the side plate.

The housing comprises: a first sidewall extending downwardly from thelower plate; a second sidewall extending from the lower plate and spacedapart from the first sidewall; and a lower cover disposed below thefirst sidewall and the second sidewall, wherein the flow path may beformed by the lower plate, the first sidewall, the second sidewall, andthe lower cover.

A ceiling surface of the flow path may be located on the lower plate; abottom surface of the flow path may be located in the lower cover; andthe side surface of the flow path may be located on the first sidewalland the second sidewall.

The vertical width of the flow path may be defined by the shortestvertical distance between the lower plate and the lower cover, and thehorizontal width of the flow path may be defined by the shortesthorizontal distance between the first sidewall and the second sidewall.

A DC-DC converter of the second embodiment may comprise: a primary coil;a secondary coil generating an induced current by the primary coil; afirst terminal and a second terminal extending from the secondary coil;an inductor coil connected to the second terminal to rectify a current;and a third terminal extending from the inductor coil, wherein the firstterminal, the primary coil, the second terminal, the inductor coil, andthe third terminal may be integrally formed.

The secondary coil may have the shape of an open ring-type platecomprising an upper surface and a lower surface, and one end thereof maybe connected to the first terminal and the other end thereof may beconnected to the second terminal.

The inductor coil may have a shape of a plate comprising an uppersurface and a lower surface grown as a three-dimensional spiral.

The inductor coil may be in the form of an angled spiral comprising aplurality of edge portions.

At least one of the first terminal, the second terminal, and the thirdterminal may comprise at least one of a bent portion and a curvedportion.

A bidirectional current may flow through the first terminal, thesecondary coil, the second terminal, the inductor coil, and the thirdterminal.

It may further comprise a first magnetic core wherein the secondary coilis disposed, and a second magnetic core wherein the inductor coil isdisposed.

It may further comprise a bus bar extending from the third terminal, andthe first terminal, the secondary coil, the second terminal, theinductor coil, the third terminal, and the bus bar thereof may beintegrally formed.

The DC-DC converter of the second embodiment may comprises: a primarycoil; a secondary coil and a tertiary coil generating an induced currentby the primary coil; a first terminal and a second terminal extendingfrom the secondary coil; a third terminal and a fourth terminalextending from the tertiary coil; a fifth terminal connected to thesecond terminal and the fourth terminal; an inductor coil extending fromthe fifth terminal to rectify a current; a sixth terminal extending fromthe inductor coil; and a bus bar extending from the sixth terminal,wherein the secondary coil, the first terminal, and the second terminalmay be integrally formed, and the tertiary coil, the third terminal, andthe fourth terminal may be integrally formed, and the fifth terminal,the inductor coil, the sixth terminal, and the bus bar may be integrallyformed.

The secondary coil is disposed on the primary coil; the tertiary coil isdisposed below the primary coil; the secondary coil is electricallyconnected to the diode module by the first terminal; and the tertiarycoil may be electrically connected to the diode module by the thirdterminal.

A DC-DC converter of the third embodiment may comprises: a housingcomprising a cooling plate; a cooling flow path disposed on one surfaceof the cooling plate; an insulating layer disposed on the other surfaceof the cooling plate; a pattern layer disposed on the insulating layer;an electric element disposed on the pattern layer; and a board spacedapart from the cooling plate and electrically connected to the patternlayer.

The electric element comprises an upper surface and a lower surface, andthe lower surface of the electric element may be soldered to the patternlayer to face the cooling plate.

The cooling plate may be formed integrally with the housing.

A plurality of heat radiating fins may be formed on one surface of thecooling plate, and the heat radiating fins may be formed as protrusionsextending to one side.

The first board and the second board may be electrically connected bysoldering of a signal leg or by press-fit method.

The signal leg may comprise: a first conducting member forming a part ofthe pattern layer; and a second conducting member being curved or bentat the first conducting member and electrically connected to the board.

The signal leg may comprise: a first conducting member electricallyconnected to the pattern layer; and a second conducting member beingcurved or bent at the first conducting member and electrically connectedto the board.

The signal leg is electrically connected to the pattern layer, andcomprises a first conducting member in the form of a plate; and a secondconducting member extending from the center of the first conductingmember to the second board side and electrically connected to the board.

The signal leg may comprise a first conducting member forming a part ofthe pattern layer and having a groove formed at the center thereof inthe form of a plate; and a second conducting member, formed with aprotruding part which is accommodated in the groove of the firstconducting member, extending from the protruding part toward the board,and being electrically connected to the board.

One end and the other end of the housing are open, and the housing maycomprise: a first cover covering the opening of the one end; and asecond cover covering the opening of the other end.

The insulating layer may be coated on the other surface of the coolingplate.

A DC-DC converter of the third embodiment comprises: a first regionwherein a flow path of a cooling fluid is formed; a second regionwherein the electronic component is disposed spaced apart from the firstregion; a cooling plate disposed between the first region and the secondregion; a main board spaced apart from the cooling plate and disposed inthe second region; an insulating layer disposed on the cooling plate; apattern layer disposed on the insulating layer; and an electric elementdisposed on the pattern layer.

Advantageous Effects

In the DC-DC converter of the first embodiment, since the difference inthe area of the vertical cross section in all portions of the flow pathis within 10%, the flow rate of the cooling material is increased andthe pressure drop width is reduced, thereby enhancing the coolingefficiency. Further, electronic components (for example, a diode module)having a large heating value and a large area can be intensively cooledby matching with an expanding portion (a portion having a largehorizontal width and a thin vertical width) of the flow path.

The second embodiment provides a DC-DC converter wherein a secondarycoil, an inductor coil, and a bus bar are integrally formed by a castingprocess, thereby enhancing the conversion efficiency thereof, andcomprising a coil module having a compact structure with reduced weight.

According to the third embodiment, the size of an electronic componentassembly and a converter can be reduced by increasing the mountingdensity of the elements in the same space by stacking of a main boardand an auxiliary board. Furthermore, by mounting an active elementhaving a high heating value on the auxiliary board directly contactingthe cooling plate, the cooling efficiency can be increased.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a DC-DC converter of the firstembodiment viewed from above.

FIG. 2 is a perspective view of the DC-DC converter of the firstembodiment wherein the upper cover is disassembled.

FIG. 3 is a perspective view of the DC-DC converter of the firstembodiment wherein the upper cover and the protective plate aredisassembled.

FIG. 4 is a cross sectional view of the DC-DC converter of the firstembodiment with reference to line A-A′.

FIG. 5 is a perspective view of the DC-DC converter of the firstembodiment with the lower cover removed and viewed from below.

FIG. 6 is a plan view of the DC-DC converter of the first embodimentwith the lower plate removed.

FIG. 7 is a plan view of the DC-DC converter of the first embodimentwith the lower cover removed.

FIG. 8 is a plan view and a side view illustrating the lower cover ofthe first embodiment.

FIG. 9(a) illustrates the “vertical cross section” of the expandingportion, and FIG. 9(b) illustrates the “vertical cross section” of theother part of the flow path respectively of the first embodiment.

FIG. 10 is a perspective view illustrating a DC-DC converter of acomparative example of the second embodiment.

FIG. 11 is a perspective view illustrating the DC-DC converter of thesecond embodiment.

FIG. 12 is a perspective view illustrating a state in which the coilmodule of the second embodiment is mounted on the first magnetic coreand the second magnetic core (the primary coil is omitted).

FIG. 13 is a perspective view illustrating the coil module of the secondembodiment (the primary coil is omitted).

FIG. 14 is a perspective view illustrating a state in which the coilmodule of a modified embodiment of the second embodiment is mounted onthe first magnetic core and the second magnetic core.

FIG. 15 is an exploded perspective view illustrating a coil moduleaccording to the modified embodiment of the second embodiment.

FIG. 16 is a perspective view illustrating the DC-DC converter of thethird embodiment with the first cover removed.

FIG. 17 is a cut-away perspective view illustrating the DC-DC converterof the third embodiment.

FIG. 18 is a cross sectional conceptual view illustrating a main board,an auxiliary board and a cooling plate of the DC-DC converter of thethird embodiment.

FIG. 19 is a conceptual diagram illustrating a signal leg of the DC-DCconverter of the third embodiment.

FIG. 20 is a cross sectional conceptual diagram illustrating a mainboard, an auxiliary board and a cooling plate respectively of a DC-DCconverter according to a modified embodiment of the third embodiment.

BEST MODE

Hereinafter, some embodiments of the present invention will be describedwith reference to exemplary drawings. In describing the referencesymbols of the components in the drawings, the same components aredenoted by the same reference numerals whenever possible, even if theyare shown on other drawings. In the following description of theembodiments of the present invention, a detailed description of knownfunctions and configurations incorporated herein will be omitted when itmay hinder the understanding of the embodiments of the presentinvention.

In describing the components of the embodiment of the present invention,terms such as first, second, A, B, (a), and (b) may be used. These termsare merely intended to distinguish the components from other components,and the terms do not limit the nature, order or sequence of thecomponents. When a component is described as being “connected,”“coupled,” or “jointed” to another component, the component may bedirectly connected, coupled, or jointed to the other component, however,it should be understood that another element may be “connected,”“coupled” or “jointed” between components.

First Embodiment

Hereinafter, “vertical direction” may mean upward and/or downwarddirection, and “horizontal direction” may mean any one of directions ona plane perpendicular to “vertical direction.” The “vertical direction”may be the horizontal width direction of the flow path 200, and the“horizontal direction” may be the horizontal width direction of the flowpath 200. The “vertical cross section” may mean a cross sectionperpendicular to the moving direction of the cooling material, and the“horizontal cross section” may be a cross section perpendicular to the“vertical cross section.”

Hereinafter, a DC-DC converter 1 of the first embodiment will bedescribed with reference to the drawings. FIG. 1 is a perspective viewof a DC-DC converter of the first embodiment viewed from above; FIG. 2is a perspective view of the DC-DC converter of the first embodimentwherein the upper cover is disassembled; FIG. 3 is a perspective view ofthe DC-DC converter of the first embodiment wherein the upper cover andthe protective plate are disassembled; FIG. 4 is a cross sectional viewof the DC-DC converter of the first embodiment with reference to lineA-A′; FIG. 5 is a perspective view of the DC-DC converter of the firstembodiment with the lower cover removed and viewed from below; FIG. 6 isa plan view of the DC-DC converter of the first embodiment with thelower plate removed; FIG. 7 is a plan view of the DC-DC converter of thefirst embodiment with the lower cover removed; FIG. 8 is a plan view anda side view illustrating the lower cover of the first embodiment; andFIG. 9(a) illustrates the “vertical cross section” of the expandingportion, and FIG. 9(b) illustrates the “vertical cross section” of theother part of the flow path respectively of the first embodiment.

DC-DC converter 1000 can be used in a vehicle. For example, the DC-DCconverter 1000 may play the role of receiving an electric current froman external power supply device (such as a lithium ion battery),boosting or lowering a voltage, supplying the voltage to an externalelectronic device (such as a motor), and thereby controlling the numberof revolutions of a motor and the like.

The DC-DC converter 1000 may comprise a housing 100, a flow path 200, aplurality of electronic components 300, an inlet 400, an outlet 500, aterminal 600, and at least one connector 700.

The housing 100 may be an exterior member of the DC-DC converter 1000.The flow path 200 may be formed in the housing 100. A plurality ofelectronic components 300 can be accommodated in the housing 100. Theplurality of electronic components 300 may be disposed inside the lowerplate 110 of the housing 100 and the flow path 200 may be located belowthe lower plate 110. The plurality of electronic components 300 can becooled by the cooling material flowing along the flow path 200. Thehousing 100 may be connected to an inlet 400, an outlet 500, a terminal600, and at least one connector 700. The material of the housing 100 maycomprise a plastic material and/or a metal material.

The housing 100 may comprise a lower plate 110, a side plate 120, aprotective plate 121, an upper cover 130, a lower cover 140, a firstsidewall 150, and a second sidewall 160.

The lower plate 110 may form a lower surface of the inner space of thehousing 100. The lower plate 110 may be roughly in the form of arectangular plate. The side plate 120 may form a side surface of theinner space of the housing 100. The side plate 120 may extend upwardfrom the edge of the lower plate 110. The housing 100 may be providedwith an inner space having an upper surface defined by the lower plate110 and the side plate 120 is open. The plurality of electroniccomponents 300 can be accommodated in the inner space of the housing100.

The inlet 400, the outlet 500, and the terminal 600 may be located atone side of the side plate 120. At least one connector 700 may belocated on the other side of the side plate 120. In this case, the inlet400, the outlet 500 and the terminal 600 may be located on the oppositeside of the at least one connector 700.

The protective plate 121 may be located in the inner space of thehousing 100. The protective plate 121 may be disposed upwardly spacedapart from a main board 310. The protective plate 121 may overlap withat least a portion of the main board 310 in the vertical direction. Thatis, a portion of the upper surface of the main board 310 may be coveredby the protective plate 121. The protective plate 121 may be a covermember for protecting a specific portion of the main board 310.

The upper cover 130 may be disposed above the side plate 120. The uppercover 130 and the side plate 120 can be combined by screws. The uppercover 130 may be roughly in the form of a rectangular plate. The innerspace of the housing 100 can be closed by the upper cover 130 of theupper cover 130. The upper cover 130 may comprise a pattern portion 131upwardly convexly protruding in a grid pattern at the center. Thepattern unit 131 may function to protect the plurality of electroniccomponents 300 accommodated in the inner space of the housing 100 byincreasing the strength of the upper cover 130.

The upper cover 130 may comprise a flange portion 132 protruding in thehorizontal direction at an edge thereof. The flange portion 132 havingthe form of a plate may be formed with a hole into which a screw isinserted.

The flow path 200 may be formed in the lower plate 110. The flow path200 may be positioned on the lower surface of the lower plate 110. Thefirst sidewall 150 and the second sidewall 160 may be horizontallyspaced apart from each other and may be downwardly extended from thelower surface of the lower plate 110. The first sidewall 150 and thesecond sidewall 160 may be connected to each other at a point where theflow path 200 is connected to the inlet 400 and the outlet 500. The flowpath 200 having an open lower surface defined by the lower plate 110,the first sidewall 150, and the second sidewall 160 may be formed. Thelower cover 140 may be located below the first sidewall 150 and thesecond sidewall 160 to close the open surface.

That is, the flow path 200 can be formed by the lower surface of thelower plate 110, the inner surface of the first sidewall 150, the innersurface of the second sidewall 160, and the upper surface of the lowercover 140. In this case, the ceiling surface of the flow path 200 can bepositioned on the lower surface of the lower plate 110, and both sidesurfaces of the flow path 200 are formed on the inner surface of thefirst sidewall 150 and the inner surface of the second sidewall 160, andthe lower surface of the flow path 200 may be positioned on the uppersurface of the lower cover 140.

The horizontal widths a and a′ of the flow path 200 may be the shortestdistance in the horizontal direction between the inner surface of thefirst sidewall 150 and the inner surface of the second sidewall 160. Thevertical widths b and b′ of the flow path 200 may be the shortestdistance in the “vertical direction” between the lower surface of thelower plate 110 and the upper surface of the lower cover 140. Thevertical widths a and a′ of the flow path 200 and the horizontal widthsb and b′ of the flow path 200 may be the vertical side and thehorizontal side of the “vertical cross section 40, 50.”

The cooling material flowing in the flow path 200 can absorb heatradiated from the plurality of electronic components 300. In this case,heat transfer occurs through the lower plate 110, and the plurality ofthe electronic components 300 can be cooled.

The lower cover 140 may be in the form of a plate. The lower cover 140may be positioned downwardly spaced apart from the lower plate 110. Theupper surface of the lower cover 140 and the lower surface of the lowerplate 110 may be connected by the first sidewall 150 and the secondsidewall 160. The lower cover 140 may comprise a protruding part 141projecting from the upper surface to the upper side (the direction inwhich the lower plate of the housing is located). The protruding part141 may be positioned corresponding to the vertical direction of theexpanding portion 240 of the flow path 200. The horizontal width abecomes larger on the “vertical cross section 40” of the expandingportion 240, but the vertical width b can be reduced. Therefore, thearea of the “vertical cross section 50” can be maintained constant(within 10%, See FIG. 9 ) at the front end (upstream side) of theexpanding portion 240, the expanding portion 240, and the rear end(downstream side). As a result, degradation of the cooling efficiencydue to the large pressure difference of the cooling material and slowingdown of the flow velocity can be prevented.

The lower cover 140 may be in the form of a plate. The lower cover 140may comprise a first sealing portion 142 and a second sealing portion143. The material of the first sealing portion 142 and the secondsealing portion 143 may comprise a sealing material such as rubber. Thefirst sealing portion 142 and the second sealing portion 143 maydownwardly protruded from the lower surface of the lower cover 140. Thefirst sealing portion 142 and the second sealing portion 143 may bespaced apart from each other in the “horizontal direction” (horizontaldirection of the flow path).

The first sealing portion 142 may overlap the first sidewall 150 in a“vertical direction.” The first sealing portion 142 can be in contactwith the lower surface of the first sidewall 150. The first sealingportion 142 may have a shape corresponding to the first sidewall 150.

The second sealing portion 143 may overlap the second sidewall 160 in a“vertical direction.” The second sealing portion 143 may be in contactwith the lower surface of the second sidewall 160. The second sealingportion 143 may have a shape corresponding to the second sidewall 160.

The first sealing portion 142 may perform the function of closing thegap between the lower cover 140 and the first sidewall 150, and thesecond sealing portion 143 may perform the function of closing the gapbetween the lower cover 140 and the second sidewall 150.

The first sealing portion 142 and the second sealing portion 143 may beconnected to each other at a position where the flow path 200 isconnected to the inlet 400 and the outlet 500 in the same manner as thefirst sidewall 150 and the second sidewall 160.

The lower cover 140 may be combined to the first sidewall 150 and thesecond sidewall 160 with screws. The lower cover 140 may comprise aguide hole 144. A guide protrusion 111 downwardly protruding from thelower plate 110 is inserted into the guide hole 144 to guide the lowercover 140. The lower cover 140 may comprise a flange portion 145. Theflange portion 145 of the lower cover 140 may be formed with a hole intowhich the screw is inserted.

The flow path 200 may be formed in the housing 100. The flow path 200may be located at one side of the housing 100. The flow path 200 may bepositioned below the lower plate 110 of the housing 100. Therefore, thelower plate 110 of the housing 100 may be a “cooling plate.” The flowpath 200 may be connected to the inlet 400. The flow path 200 may beconnected to the outlet 500. The most upstream of the flow path 200 maybe connected to the inlet 400 to be supplied with the cooling material.The downstream end of the flow path 200 may be connected to the outlet500 to discharge the cooling material. The cooling material flows alongthe flow path 200 and can cool the heat generated by the plurality ofelectronic components 300. Various types of heat exchange fluids (e.g.,cooling water) may be used as cooling materials.

The flow path 200 may be formed by a lower plate 110, a first sidewall150, a second sidewall 160, and a lower cover 140. The bottom surface ofthe flow path 200 may be positioned on the upper surface of the lowercover 140. That is, the upper surface of the lower cover 140 may be thebottom surface of the flow path 200. The ceiling of the flow path 200may be positioned on the lower surface of the lower plate 110. That is,the lower surface of the lower plate 110 may be a ceiling surface of theflow path 200. Both side surfaces of the flow path 200 may be located onthe inner surfaces of the first sidewall 150 and the second sidewall160, respectively. That is, the inner side surfaces of the firstsidewall 150 and the second sidewall 160 could be both sides of the flowpath 200.

The horizontal widths a and a′ of the flow path 200 may be defined bythe shortest distance in the “horizontal direction” between the innersurface of the first sidewall 150 and the inner surface of the secondsidewall 160. The vertical widths b and b′ of the flow path 200 may bedefined by the shortest distance in the “vertical direction” between thelower surface of the lower plate 110 and the upper surface of the lowercover 140. The horizontal widths b and b′ of the flow path 200 and thevertical widths a and a′ of the flow path 200 may be different dependingon the moving direction of the cooling material.

For example, in the expanding portion 240, the horizontal width a of theflow path 200 may be greater than the horizontal width a′ of the frontend (upstream side of the expanding portion) or the rear end (downstreamside of the expanding portion) of the expanding portion 240. Also, inthe expanding portion 240, the vertical width b of the flow path 200 maybe smaller than the vertical width b′ of the front end (upstream side ofthe expanding portion) or the rear end (downstream side of the expandingportion) of the expanding portion 240.

The flow path 200 may comprise an inlet portion 210, a first curvedportion 220, a second curved portion 230, an expanding portion 240, andan outlet portion 250. The upstream of the inlet 210 may be connected tothe inlet 400. The downstream portion of the outlet portion 250 may beconnected to the outlet 500. The downstream of the inlet portion 210 canbe connected to the upstream of the first curved portion 220; thedownstream of the first curved portion 220 can be connected to theupstream of the second curved portion 230; the downstream of the secondcurved portion 230 may be connected to the upstream of the expandingportion 240; and the downstream of the expanding portion 240 may beconnected to the upstream of the outlet portion 250. Accordingly, thecooling material introduced from the inlet 400 sequentially movesthrough the inlet portion 210, the first curved portion 220, the secondcurved portion 230, the expanding portion 240, and the outlet portion250, and then can be discharged through the outlet 500.

The inlet portion 210 and the outlet portion 250 may be disposedadjacent to each other. The inlet portion 210 and the outlet portion 250may be disposed in parallel with each other. The inlet portion 210 andthe outlet portion 250 may be spaced apart in the “horizontal direction”(horizontal width direction of the flow path). The first curved portion220 and the expanding portion 240 may be disposed adjacent to eachother. The first curved portion 220 and the expanding portion 240 can bespaced apart in the “horizontal direction” (horizontal width directionof the flow path). The second curved portion 230 may be a point at whichthe flow direction of the cooling water in the flow path 200 iscompletely inverted (turn-up or U-turn). The second curved portion 230may be formed in the shape of a letter “U.” One end of the second curvedportion 230 may be connected to the first curved portion 220. The otherend of the second curved portion 230 may be connected to the expandingportion 240. The second curved portion 230 may connect the first curvedportion 220 and the expanding portion 240. The direction of movement ofthe cooling material in the inlet portion 210 and the outlet portion 250disposed in parallel may be reversed by the second curved portion 230.

The first curved portion 220 may have a convex curvature in a directionin which the expanding portion 240 is located. The shortest “horizontaldirection” distance between the first curved portion 220 and theexpanding portion 240 may be less than the shortest “horizontaldirection” distance between the inlet portion 210 and the outlet portion250. The curvature of the second curved portion 230 may be convex(U-shaped) in a direction opposite to the direction in which the inletportion 210 and the outlet portion 250 are located. The expandingportion 240 may be convexly curved in the “horizontal direction.” Thewidth a of the flow path 200 in the expanding portion 240 may be greaterthan the width a′ of another portion of the flow path 200 (for example,the front end or the rear end of the expanding portion 240).

In the first embodiment, the inlet portion 210, the first curved portion220, the second curved portion 230, the expanding portion 240, and theoutlet portion 250 are formed in the flow path 200, so as to effectivelycool the heating element 320.

Each of the plurality of heating elements 320 comprises an inductor 321,a transformer 322, a Zero-Voltage-Switching (ZVS) inductor 323, aswitching module 324, a diode module 325, and the like, wherein theinlet portion 210 may be disposed to correspond to the inductor 210 inthe vertical direction (horizontal direction of the flow path); thefirst curved portion 220 may be disposed so as to be verticallycorresponding to the transformer 220; the front end (the upstream sideof the second curved portion) of the second curved portion 230 may bedisposed so as to be vertically aligned with the ZVS inductor 323; thesecond curved portion 230 may be disposed so as to be verticallycorresponding to the switching module 324; and the expanding portion 240may be disposed so as to be vertically corresponding to the diode module240 in the vertical direction (see FIG. 7 ).

In this case, the curvature of the first curved portion 220 is convexlyformed in a direction in which the expanding portion 240 is located soas to efficiently cool the transformer 322 having a larger “horizontalarea” than the inductor 321 (to cool the center portion of thetransformer).

In addition, the expanding portion 240 has a larger “horizontal area”than the other portions of the flow path 200 in order to efficientlycool the diode module 325 having a high heating value. The expandingportion 240 can be disposed between the transformer 322 and the diodemodule 325 as well as the diode module 325 due to its wide “horizontalarea,” so that a conducting member 326 which electrically connects thetwo together can also be cooled. To this end, the maximum “horizontalarea” 10, the largest area of the horizontal area of the expandingportion, of the expanding portion 240 may be more than 90% of themaximum “horizontal area” 20, the largest area of the horizontal area ofthe diode module, of the diode module 325. Also, the area 30 thatoverlaps the diode module 325 in the “vertical direction” at the maximum“horizontal area” 10 of the expanding portion 240 may be more than 30%.

On the other hand, the flow path 200 of the first embodiment ischaracterized in that the “vertical cross section” 50 is uniform alongthe moving direction of the cooling material. The difference between thelargest portion and the smallest portion of the area of the “verticalcross section” 50 of the flow path 200 may be within 10% or less. Thearea of the “vertical cross section” 50 of the flow path 200 may be thesame along the moving direction of the cooling material. As a result,the flow rate of the cooling material can be increased and the pressuredrop width can be reduced, thereby improving the cooling efficiency.

The width a of the flow path 200 may be widened in the expanding portion240, so that the diode module 325 can be efficiently cooled. As aresult, the area of the “vertical cross section” 40 in the expandingportion 240 can be larger than the area of the “vertical cross section”50 of the other portion of the flow path 200. This may be contradict tothe intention of the first embodiment to make the “vertical crosssection” 50 of the flow path 200 be uniform.

In order to solve this problem, in the first embodiment, the verticalwidth b of the “vertical cross section” 40 in the expanding section 240is set to be smaller than the vertical width b′ of the “vertical crosssection” 50 of the other portion (for example, the front end of theexpanding portion) of the flow path 200. As a result, the area of the“vertical cross section” 40 of the expanding portion 240 may be the sameas or similar to the area of the “vertical cross section” 50 (Refer toFIG. 9 ).

To this end, the protruding part 141 may be positioned on the bottomsurface of the expanding portion 240. That is, the protruding part 141may be positioned in the lower cover 140 at a position corresponding tothe “vertical direction” with respect to the expanding portion 240. As aresult, the vertical width b of the expanding portion 240 can be widenedwhile maintaining the height of the first sidewall 150 and the secondsidewall 160.

The protruding part 141 may be protruded from the bottom surface of theexpanding portion 240 in a direction in which the lower plate 110 ispositioned. The protruding height of the protruding part 141 mayincrease and then decrease along the moving direction of the coolingmaterial. The “vertical cross section” of the protruding part 141 mayhave the shape of a rectangle (see FIG. 8 (A)). The area of the“vertical cross section” of the protruding part 141 may increase andthen decrease along the moving direction of the cooling material. The“horizontal cross section” of the protruding part 141 may be a shape inwhich the curvature is convexly formed towards the lower plate 110 islocated (see FIG. 8 (B)). The area of the “horizontal cross section” ofthe protruding part 141 can be reduced as it travels from the center ofthe horizontal width a of the expanding portion 240 toward the edge.

The outlet portion 250 may comprise a curved portion 251. The curvedportion 251 may be positioned between the outlet portion 250 and theoutlet 500. The curved portion 251 may be located at the end ofdownstream of the outlet portion 250. In the curved portion 251, thebottom surface of the flow path 200 may be upwardly inclined as ittravels towards the downstream side.

The plurality of electronic components 300 may be located in the innerspace of the housing 100. The plurality of electronic components 300 maybe disposed above the lower plate 110 (cooling plate). Below the lowerplate 110 (cooling plate), a flow path 200 through which the coolingmaterial flows may be formed so that the heat generated by the pluralityof electronic components 300 can be cooled.

The plurality of electronic components 300 may comprise a main board310, a plurality of heating elements 320, a first auxiliary board 330,and a second auxiliary board 340.

The main board 320 may be disposed above the lower plate 110. The mainboard 320 may be upwardly spaced apart from the upper plate 110. Variouselectronic component chips may be mounted on the main board 320. Acircuit for interconnecting various electronic component chips may beformed on the main board 320. The main board 320 may be electricallyconnected to the first auxiliary board 330 and the second auxiliaryboard 340.

One of the plurality of heating elements 320 may overlap with theexpanding portion 240 in a “vertical direction.” The maximum “horizontalarea” 10 of the expanding portion 240 may be at least 90% of the maximum“horizontal area” 20 of one of the plurality of heating elements 320overlapping in the “vertical direction.” The area 30 overlapping withone of the plurality of heating elements 320 overlapping in the“vertical direction” at the maximum “horizontal area” 10 of theexpanding portion 240 may be more than 30%. In this case, among theplurality of heating elements 320, the heating element overlapping inthe “vertical direction” with the expanding portion 240 may be the diodemodule 325.

Each of the plurality of heating elements 320 may comprise an inductor321, a transformer 322, a zero-voltage-switching (ZVS) inductor 323, aswitching module 324, a diode module 325, and a conducting member 326.

The inductor 321, the transformer 322 and the zero-voltage-switching(ZVS) inductor 323 may be disposed on the upper surface of the lowerplate 110. The switching module 324 may be mounted on the firstauxiliary board 330. The diode module 325 may be mounted on the secondauxiliary board 340. The conducting member 326 may be a member thatelectrically connects the transformer 322 and the diode module 325.

The inductor 321, the transformer 322 and the zero-voltage-switching(ZVS) inductor 323 may be electrically connected to the main board 320by a conducting member. The main board 320 may not be disposed in aportion where the inductor 321, the transformer 322 and thezero-voltage-switching (ZVS) inductor 323 are disposed in the lowerplate 110.

The inductor 321 can perform the function of smoothing the current andreducing the ripple current. Further, the current flow can be madecontinuous. That is, the inductor 321 may perform the function ofrectifying current. The inductors 321 may be disposed so as tocorrespond to the inlet portion 210 of the flow path 200 in a “verticaldirection.”

The transformer 322 can perform the function of boosting or reducingcurrent. The transformer 322 can perform a function of converting power.The transformer 322 may be disposed to correspond to the first curvedportion 220 of the flow path 200 in a “vertical direction.”

The zero-voltage-switching (ZVS) inductor 323 can control a light load.That is, it may be an auxiliary inductor for improving light loadefficiency. The zero-voltage-switching (ZVS) inductor 323 may bedisposed in a “vertical direction” corresponding to the front end of thesecond curved portion 230.

The switching module 324 can control ON/OFF of the current. Further, theswitching module 324 can be integrated with the transformer 322 to lowerthe DC input voltage and output it. The switching module 324 may bedisposed to correspond to the second curved portion 230 in the “verticaldirection.”

The diode module 325 can control the direction of the current. That is,the diode module 325 can perform the function of moving the current in aspecific direction. The diode module 325 may be disposed correspondingto a “vertical direction” with respect to the expanding portion 240.

The conducting member 326 can electrically connect the transformer 322and the diode module 325.

The first auxiliary board 330 and the second auxiliary board 340 may bepositioned below the main board 310. The first auxiliary board 330 andthe second auxiliary board 340 may be downwardly spaced apart from themain board 310. The first auxiliary board 330 and the second auxiliaryboard 340 may be disposed between the lower plate 110 and the main board310. The first auxiliary board 330 and the second auxiliary board 340may be electrically connected to the main board 310 by a separateconducting member. The switching module 324 may be mounted on the firstauxiliary board 330. The diode module 325 may be mounted on the secondauxiliary board 340.

The inlet 400 and the outlet 500 may be located at one side of the sideplate 120 of the housing 100. The external cooling material may flowinto the flow path 200 through the inlet 400. The cooling material maybe discharged from the flow path 200 through the outlet 500.

The terminal 600 may be located at one side of the side plate 120 of thehousing 100. The terminal 600 may be located between the inlet 400 andthe outlet 500. An external power supply may be electrically connectedto the terminal 600. That is, an external current may be supplied to theplurality of electronic components 300 through the terminal 600.

At least one connector 700 may be located on the other side of the sideplate 120 of the housing 100. The at least one connector 700 may belocated on the opposite side of the inlet 400 and the outlet 500. The atleast one connector 700 may be electrically connected to an externalelectronic component (for example, an electric motor).

Second Embodiment

Hereinafter, a DC-DC converter 2001 according to a comparative exampleof the present second embodiment will be described with reference to thedrawings. FIG. 10 is a perspective view illustrating a DC-DC converterof a comparative example of the second embodiment.

The DC-DC converter 2001 of the present comparative embodiment may be aDC-DC converter used in a vehicle. For example, the DC-DC converter 1000may play the role of receiving an electric current from an externalpower supply device (such as a lithium ion battery), boosting orlowering a voltage, supplying the voltage to an external electronicdevice (such as a motor), and thereby controlling the number ofrevolutions of a motor and the like. The DC-DC converter 2001 maycomprise a case 2010, a conversion unit 2020, an inductor unit 2030, abus bar (not shown), and an external terminal 2050.

The case 2010 may be an external member of the DC-DC converter 2001. Inthe case 2001, an internal space is formed to accommodate the conversionunit 2020, the inductor unit 2030, and a bus bar (not shown). The case2010 may be formed with a first, a second, a third, a fourth, and afifth case terminals 2010 a, 2010 b, 2010 c, 2010 d, and 2010 e, and anexternal terminal 2050.

The conversion unit 2020 may comprise a primary coil 2021 and asecondary coil 2022 disposed apart from the primary coil 2021. A currentsupplied from an external power supply device flows through the primarycoil 2021, and the secondary coil 2022 may interact electromagneticallywith the primary coil 2021 to output the converted current. The primarycoil 2021 may be electrically connected to the first and the second caseterminals 2010 a and 2010 b and may be supplied with a current from anexternal power supply device. The secondary coil 2022 may beelectrically connected to the third, the fourth, and the fifth caseterminals 2010 c, 2010 d, and 2010 e. In this case, the third caseterminal 2010 c and the fourth case terminal 2010 d may be electricallyconnected to the diode module. Accordingly, the secondary coil 2022 canbe electrically connected to the diode module. In addition, the fifthcase terminal 2010 e may be electrically connected to the inductor unit2030.

The inductor unit 2030 may comprise an inductor coil 2031. The inductorcoil 2031 may be in the form of a three-dimensional spiral. Thesethree-dimensional spirals are sometimes referred to as “screw spirals.”The initial portion of the inductor coil 2031 may be electricallyconnected to the fifth case terminal 2010 e. The initial portion of theinductor coil 2031 may be electrically connected to the secondary coil2022 at the fifth case terminal 2010 e. The end of the inductor coil2031 may be electrically connected to the external terminal 2050 througha bus bar (not shown). The inductor coil 2031 can be supplied with theconverted current output from the secondary coil 2022. Further, theinductor coil 2031 can rectify the converted current output from thesecondary coil 2022. Further, the current rectified by the inductor coil2031 can be supplied to the external terminal 2050.

By summarizing the above description, when the current is supplied fromthe external power device to the primary coil 2021, the secondary coil2022 can output the boosted or lowered converted current. The convertedcurrent output from the secondary coil 2022 can be rectified in theinductor coil 2031. The rectified current may be supplied to an externalelectronic device (for example, a motor) through the external terminal2050. In this case, the secondary coil 2022 may be electricallyconnected to one side of the external terminal 2050 through the thirdcase terminal 2010 c. The secondary coil 2022 may be electricallyconnected to the other end of the external terminal 2050 through thefifth case terminal 2010 e, the inductor coil 2031, and the bus bar2040. Accordingly, a circuit may be formed wherein a current generatedin the secondary coil 2022 is rectified in the inductor coil 2031 andbeing supplied to the external electronic device. As a result, theexternal electronic device connected to the external terminal 2050 canbe supplied with a current that is converted in the secondary coil 2022and rectified in the inductor coil 2031.

In the present comparative embodiment of the second embodiment, thesecondary coil 2022, the inductor coil 2031, and the bus bar (not shown)are electrically connected to each other, however, each of them isseparately manufactured as a single member. Thereafter, the secondarycoil 2022 and the inductor coil 2031 are bolt-coupled together at thefifth case terminal 2010 e so that they may be electrically connected.In addition, the inductor coil 2031 and the bus bar (not shown) may alsobe bolt-coupled together so that they may be electrically connected. Agap may be generated in this bonding process, which leads not only todeterioration of electrical characteristics but also to an increase incontact resistance, thereby lowering the conversion efficiency of theDC-DC converter 2001. In order to manufacture each of the secondary coil2022 and the inductor coil 2031, complicated manufacturing processessuch as sheet press cutting, bolt hole punching, bending, forging, andthe like are required. As a result, there is a problem in the aspects ofproduction efficiency.

Hereinafter, the DC-DC converter 2100 of the present second embodimentwill be described with reference to the drawings. FIG. 11 is aperspective view illustrating the DC-DC converter of the secondembodiment; FIG. 12 is a perspective view illustrating a state in whichthe coil module of the second embodiment is mounted on the firstmagnetic core and the second magnetic core (the primary coil isomitted); and FIG. 13 is a perspective view illustrating the coil moduleof the second embodiment (the primary coil is omitted).

The DC-DC converter 2100 of the second embodiment may comprise a case2110, a conversion unit 2120, an inductor unit 2130, a bus bar 2140, anda first external terminal 2150. Among these, the assembly of thesecondary coil 2122 of the conversion unit 2120, the first and thesecond terminals 2123 and 2124 and the inductor coil 2131 of theinductor unit 2130, and the third terminal 2132 and the bus bar 2140 maybe referred to as a “coil module.” Among the “coil module,” the first,the second, and the third terminals 2123, 2124, and 2132, and the busbar 2140 are conducting members for electrical connection, and may beomitted by a request based on design aspects. The secondary coil 2122,the first and the second terminals 2123 and 2124, the inductor coil2131, the third terminal 2132, and the bus bar 2140 may be integrallyfabricated by casting. That is, among the “coil module,” the secondarycoil 2122, the first and the second terminals 2123 and 2124, theinductor coil 2131, the third terminal 2132, and the bus bar 2140 can beintegrally formed.

By summarizing the above description, there may be a difference in thatthe DC-DC converter 2100 of the second embodiment has the secondary coil2122, the inductor coil 2131, and the bus bar 2140 are integrallyfabricated by “casting” when compared with the DC-DC converter 2010 ofthe comparative example. That is, the secondary coil 2122, the inductorcoil 2131, and the bus bar 2140 may be integrally formed. Therefore,complicated processes such as sheet press cutting, bolt hole punching,bending, forging, and the like for manufacturing of the secondary coil2122 and the inductor coil 2131 may be omitted. In addition,bolt-coupling for connecting the secondary coil 2122 and the inductorcoil 2131 can be omitted. In addition, bolt-coupling for connecting theinductor coil 2131 and the bus bar 2140 can be omitted (as a result, thefifth case terminal 2010 e of the comparative embodiment forbolt-coupling also can be omitted). In such an integral type coilmodule, since bolt-coupling is not necessary, there is no gap that canbe occurred by bolt-coupling. As a result, the problem of thebolt-coupling described above does not occur, and the conversionefficiency of the DC-DC converter 2100 can be increased.

The case 2110 may be an exterior member of the DC-DC converter 2100. Aninternal space is formed in the case 2110 to accommodate the conversionunit 2120, the inductor unit 2130, and the bus bar 2140. A first, asecond, and a third case terminals 2110 a, 2110 b, and 2110 c and afirst external terminal 2150 may be formed in the case 2110.

The conversion unit 2120 can be supplied with a current from an externalpower supply device. The conversion unit 2120 can convert an externalcurrent and output. The conversion unit 2120 may comprise a primary coil2121, a secondary coil 2122, a first terminal 2123, a second terminal2124, and a first magnetic core 2125.

The primary coil 2121 can be supplied with current from the externalpower supply device. The primary coil 2121 is in the form of athree-dimensional spiral, and the initial portion of the spiral growthcan be electrically connected to the first case terminal 2100 a by theconducting member. The end portion of the spiral growth of the primarycoil 2121 may be electrically connected to the second case terminal 2100b by a conducting member. The first and the second case terminals 2100 aand 2100 b may be electrically connected to an external power supplydevice. As a result, a current supplied from the external power supplydevice can flow through the primary coil 2121. In the presentembodiment, the primary coil 2121 is a three-dimensional spiral havingcurved lines. However, the shape of the spiral of the primary coil 2121is not limited thereto.

The secondary coil 2122 may be a component of a “coil module.” Thesecondary coil 2122 may be disposed apart from the primary coil 2121.The secondary coil 2122 may be disposed above the primary coil 2121. Thesecondary coil 2122 may electromagnetically interact with the primarycoil 2121. In the secondary coil 2122, a current is induced by thecurrent of the primary coil 2121, and an induced current can begenerated. The induced current generated in the secondary coil 2122 maybe a current that is boosted or lowered by the current flowing throughthe primary coil 2121.

The secondary coil 2122 may have the shape of an open ring-type platecomprising an upper surface and a lower surface. The initial portion(one end) of the secondary coil 2122 may be a shape extended from thefirst terminal 2123. The end portion (other end) of the secondary coil2122 may be connected to the second terminal 2124. That is, one end ofthe secondary coil 2122 may be electrically connected to the firstterminal 2123, and the other end of the secondary coil 2122 may beelectrically connected to the second terminal 2124. The secondary coil2122 and the first and the second terminals 2123 and 2124 may beintegrally formed. However, the shape of the secondary coil 2122 is notlimited to the ring-type as described above. For example, the secondarycoil 2122 may be disposed in a three-dimensional spiral shape, spacedvertically or horizontally from the primary coil 2121. In addition, thesecondary coil 2122 may be a three-dimensional spiral shape interleavingwith the primary coil 2121 while being spaced apart from each other. Inthis case, the primary and the secondary coils 2121 and 2122 can beformed into one double-layered three-dimensional spiral.

The first terminal 2123 may be a component of the “coil module.” Thefirst terminal 2123 may be a member for electrically connecting thesecondary coil 2122 to an external terminal. The first terminal 2123 maybe a plate-shaped conducting member. The first terminal 2123 may be ashape extended from the above towards the lower side (verticaldirection). One end of the first terminal 2123 may be located at thetop. The other end of the first terminal 2123 may be located at thelower portion. One end of the first terminal 123 may be curved or bentand extended in the vertical direction at the initial portion of thesecondary coil 2122. The other end of the first terminal 2123 may becurved or bent in the horizontal direction and then divided into a firstand a second terminal portions 2123 a and 2123 b which will be describedlater. According to the above description, the first terminal 2123 maycomprise at least one of a bent portion and a curved portion. In thiscase, the bent or curved angle of the bent portion or the curved portionmay be right angled.

One end of the first terminal 2123 may be electrically connected to theinitial portion of the secondary coil 2122. The other end of the firstterminal 2123 can be divided into a first terminal portion 2123 a and asecond terminal portion 2123 b. The first terminal portion 2123 a may beelectrically connected to the third case terminal 2100 c bybolt-coupling. Therefore, a hole for bolt-coupling may be formed on thefirst terminal portion 2123 a. And the second terminal portion 2123 bmay be electrically connected to the fourth case terminal 2110 d bybolt-coupling. Therefore, a hole for bolt-coupling may be formed on thesecond terminal portion 2123 b. The third case terminal 2110 c and thefourth case terminal 2100 c may be electrically connected to a diodemodule (not shown). Accordingly, the secondary coil 2122 can beelectrically connected to the diode module through the first terminal2123.

Second terminal 2124 may be a component of a “coil module.” The secondterminal 2124 may be extended from the secondary coil 2122. The secondterminal 2124 may be a member for electrically connecting the secondarycoil 2122 and the inductor coil 2131. The second terminal 2124 may be aplate-shaped conducting member. The second terminal 2124 may be a shapeextended from the above towards the lower side (vertical direction) andthen extended towards the inductor coil 2131 (horizontal direction). Oneend of the second terminal 2124 may be curved or bent and extended inthe vertical direction at the end portion of the secondary coil 2122.The middle portion of the second terminal 2124 may be curved or bent andextended toward the inductor coil 2131 (horizontal direction). The otherend of the second terminal 2124 may be connected to the initial portionof the inductor coil 2131. According to the above description, thesecond terminal 2124 may comprise at least one of a bent portion and acurved portion. In this case, the bent or curved angle of the bentportion or the curved portion may be right angled.

One end of the second terminal 2124 may be electrically connected to theend portion of the secondary coil 2122. The other end of the secondterminal 2124 may be electrically connected to the initial portion ofthe inductor coil 2131. By summarizing the above description, thecurrent generated in the secondary coil 2122 can be supplied to theinductor coil 2131 through the second terminal 2124.

A primary coil 2121 and a secondary coil 2122 may be disposed in thefirst magnetic core 2125. The first magnetic core 2125 may be aferromagnetic member that collects magnetic flux lines of the primarycoil 2121 and the secondary coil 2122 to increase the strength of themagnetic field. The first magnetic core 2125 may comprise a first bobbinportion 2125 a and a first support portion 2125 b. The first supportportion 2125 b is formed in the shape of a block having an inner spaceat the center thereof, and a first bobbin portion 2125 a is formed inthe inner space so that the primary coil 2121 may be supported. Theprimary coil 2121 and the secondary coil 2122 may be wound around thefirst bobbin portion 2125 a. The outer surface of the first magneticcore 2125 may be coated with an insulating material. The first magneticcore 2125 may have various shapes according to the request based on thedesign aspects.

The inductor unit 2130 can rectify the current generated in theconversion unit 2120. The inductor unit 2130 may comprise an inductorcoil 2131, a third terminal 2132, and a second magnetic core 2133.

The inductor coil 2131 may be a component of a “coil module.” Theinductor coil 2131 can be supplied with the converted current from thesecondary coil 2122. The inductor coil 2131 can rectify the convertedcurrent. The inductor coil 2131 may be connected to the first externalterminal 2150 to supply a rectified current.

The inductor coil 2131 may have a shape of a plate comprising an uppersurface and a lower surface grown as a three-dimensional spiral. Thatis, the inductor coil 2131 may be in the form of a three-dimensionalspiral, and the initial portion (lower portion) of the spiral growth maybe electrically connected by the second terminal 2124 and the secondarycoil 2122. That is, the inductor coil 2131 may be extended from theother end of the second terminal 2124. An end portion (upper portion) ofthe spiral growth of the inductor coil 2131 can be electricallyconnected to the first external terminal 2150 through the bus bar 2140.In this embodiment, the inductor coil 2131 is a three-dimensional spiralhaving curved lines. However, the shape of the inductor coil 2131 is notlimited thereto.

The third terminal 2132 may be a component of the “coil module.” Thethird terminal 2132 may be a member for electrically connecting theinductor coil 2131 to an external terminal. The third terminal 2132 maybe a plate-shaped conducting member. The third terminal 2132 may be ashape extended from the above towards the lower side (verticaldirection). One end of the third terminal 2132 may be located at thetop. The other end of the third terminal 2132 may be located at thelower portion. One end of the third terminal 2132 may be curved or bentand extended in the horizontal direction (direction opposed to thehorizontal growth direction of the spiral) at the end portion of theinductor coil 2131. Thereafter, one end of the third terminal 2132 maybe curved or bent and extended toward the horizontal direction (fromabove towards the lower side). The other end of the third terminal 2132may be curved or bent in the horizontal direction (the direction of thebus bar 2140) and then may be connected to the bus bar 2140. Accordingto the above description, the third terminal 2132 may comprise at leastone of a bent portion and a curved portion. In this case, the bent orcurved angle of the bent portion or the curved portion may be rightangled.

One end of the third terminal 2132 may be electrically connected to theend of the inductor coil 2131. The other end of the third terminal 2132may be electrically connected to the bus bar 2140. Thus, the inductorcoil 2131 can be electrically connected to the bus bar 2140 through thethird terminal 2132. The bus bar 2140 is electrically connected to theexternal terminal 2150 so that the inductor coil 2131 can beelectrically connected to the external terminal 2150 through the thirdterminal 2132 and the bus bar 2140.

An inductor coil 2131 may be disposed in the second magnetic core 2133.The second magnetic core 2133 may be a ferromagnetic member thatcollects magnetic flux lines of the inductor coil 2131 to increase thestrength of the magnetic field. The second magnetic core 2133 maycomprise a second bobbin portion 2133 a and a second support portion2133 b. The first support portion 2133 b is in the form of a blockhaving an inner space at the center, and a second bobbin portion 2133 ais formed in the inner space to support the inductor coil 2131. Theinductor coil 2131 may be wound around the second bobbin portion 2133 a.The outer surface of the second magnetic core 2133 may be coated with aninsulating material. The second magnetic core 2133 may have variousshapes according to the request based on the design aspects.

Bus bar 2140 may be a component of a “coil module.” The bus bar 2140 maybe in the form of an elongated plate extending towards the externalterminal 2150. One end of the bus bar 2140 may be electrically connectedto the other end of the third terminal 2132. The other end of the busbar 2140 may be electrically connected to the first external terminal2150. In this case, the other end of the bus bar 2140 and the firstexternal terminal 2150 may be bolt-coupled together. To this end, athird terminal portion 2140 a may be formed at the other end of the busbar 2140. Further, a bolt hole may be formed in the third terminalportion 2140 a. Therefore, the rectified current of the inductor coil2131 can be supplied to the external terminal 2150 through the thirdterminal 2132 and the bus bar 2140.

The external terminal 2150 can be connected to an external electronicdevice (e.g., a vehicle motor). The external electronic device isconnected to the external terminal 2150 to be supplied with a current.Therefore, the external electronic device can be supplied with thecurrent converted in the secondary coil 2122, and rectified by theinductor coil 2131. That is, the external electronic device can besupplied with the rectified and converted current having the ratedvoltage converted through the secondary coil 2122, and the noisefiltered through the inductor coil 2131.

A bidirectional current may flow through the first terminal 2123, thesecondary coil 2122, the second terminal 2124, the inductor coil 2131,the third terminal 2132, and the bus bar 2140 that are mentioned above.Therefore, for example, when the electric vehicle travels downhill andthe external electronic device (motor) generates electric current like agenerator, it may be supplied to the secondary coil 122 through thefirst terminal 2123, the second terminal 2124, the inductor coil 2131,the third terminal 2132, and the bus bar 2140. In this case, aninduction current is generated in the primary coil 2121 so that theexternal power source device (lithium ion battery) can be charged.

As described above, in the “coil module” of the second embodiment, atleast one of the first terminal 2123, the second terminal 2124, and thethird terminal 2132 may comprise at least one of a bent portion or acurved portion. This is to provide the “coil module” with a compact andstable support structure.

On the other hand, the plate constituting the “coil module” for avehicle is a thin and wide plate comprising an upper surface and a lowersurface. This is because it is necessary to have a large resistancevalue in order to handle the electric capacity being supplied to variouselectronic components of the vehicle. However, when the bent portion orthe curved portion is formed by bend forming as described in thecomparative embodiment, the bent portion or the curved portion isinevitably worn, damaged or distorted due to the shape of the plate andthe characteristics of the forming process. This is undesirable becauseof the degradation in the electrical properties and durability of the“coil module.”

However, since the first terminal 2123, the second terminal 2124 and thethird terminal 2132 of the “coil module” according to the secondembodiment are formed by “casting,” a bent portion or a curved portionhaving the predetermined shape set at the design step can be formed dueto the characteristics of the forming process. Therefore, the “coilmodule” of the second embodiment can have a compact and stable supportstructure, and at the same time, the electrical characteristics anddurability can be improved.

Hereinafter, a modified embodiment of the second embodiment will bedescribed with reference to the drawings. FIG. 14 is a perspective viewillustrating a state in which the coil module according to the modifiedembodiment of the second embodiment is mounted on the first and thesecond magnetic cores, and FIG. 15 is an exploded perspective viewillustrating a coil module according to the modified embodiment of thesecond embodiment.

The modified embodiment of the second embodiment is different from thesecond embodiment in the “coil module.” The modified embodiment of thesecond embodiment has substantially the same technical idea as that ofthe second embodiment other than the above differences. Therefore, thesecond embodiment can be analogically applied to the modified embodimentof the second embodiment. Hereinafter, description of portions havingsubstantially the same technical ideas as those of the second embodimentwill be omitted.

The “coil module” in the modified embodiment of the second embodimentmay comprise a conversion unit, an inductor unit, and a bus bar. In thiscase, the conversion unit comprises a primary coil 2121-1, a secondarycoil 2122-1, a tertiary coil 2122-2, a first terminal 2123-1, a secondterminal 2124-1, a third terminal 2124-2, and a fourth terminal 2123-2.The inductor unit may comprise an inductor coil 2131-1, a fifth terminal2133-1, and a sixth terminal 2132-1. The most important feature in themodified embodiment of the second embodiment is that the coils where theinduced current caused by the primary coil flows through are thesecondary coil and the tertiary coil, that is, a total of two.

The primary coil 2121-1 can be supplied with current from the externalpower supply device. The primary coil 2121-1 is in the form of athree-dimensional spiral, and the initial portion of the spiral growthcan be electrically connected to a first case terminal 2100 a throughthe conducting member. The end portion of the spiral growth of theprimary coil 2121-1 can be electrically connected to a second caseterminal 2100 b by the conductive line.

The secondary coil 2122-1 may be disposed apart from the primary coil2121-1. The secondary coil 2122-1 may be located above the primary coil2121-1. The secondary coil 2122-1 may electromagnetically interact withthe primary coil 2121-1. In the secondary coil 2122-1, a current isinduced by the current of the primary coil 212-11 so that an inducedcurrent may be generated. The induced current generated in the secondarycoil 2122-1 may be a current that is boosted or lowered by the currentflowing through the primary coil 2121-1.

The secondary coil 2122-1 may have the shape of an open ring-type platecomprising an upper surface and a lower surface. The initial portion(one end) of the secondary coil 2122-1 may be a shape extended from thefirst terminal 2123-1. The end portion (other end) of the secondary coil2122-1 may be connected to the second terminal 2124-1. That is, one endof the secondary coil 2122-1 may be electrically connected to the firstterminal 2123-1, and the other end of the secondary coil 2122-1 may beelectrically connected to the second terminal 2124-1. The secondary coil2122-1 and the first and the second terminals 2123-1 and 2124-1 may beintegrally formed. However, the shape of the secondary coil 2122-1 isnot limited to the ring-type as described above. For example, thesecondary coil 2122-1 may be disposed in a three-dimensional spiralshape, spaced vertically or horizontally from the primary coil 2121-1.In addition, the secondary coil 2122-1 may be a three-dimensional spiralshape interleaving with the primary coil 2121-1 while being spaced apartfrom each other. In this case, the primary and the secondary coils2121-1 and 2122-1 can be formed into one double-layeredthree-dimensional spiral.

The first terminal 2123-1 may be a member for electrically connectingthe secondary coil 2122-1 to an external terminal. The first terminal2123-1 may be a plate-shaped conducting member. The first terminal2123-1 may be a shape extended from the above towards the lower side(vertical direction). One end of the first terminal 2123-1 may belocated at the top. The other end of the first terminal 2123-1 may belocated at the lower portion. One end of the first terminal 123-1 may becurved or bent and extended in the vertical direction at the initialportion of the secondary coil 2122-1. The other end of the firstterminal 2123-1 may be curved or bent in the horizontal direction andthen divided into a first and a second terminal portions 2123-1 a and2123-1 b which will be described later. According to the abovedescription, the first terminal 2123-1 may comprise at least one of abent portion and a curved portion. In this case, the bent or curvedangle of the bent portion or the curved portion may be right angled.

One end of the first terminal 2123-1 may be electrically connected tothe initial portion of the secondary coil 2122-1. The other end of thefirst terminal 2123-1 can be divided into a first terminal portion2123-1 a and a second terminal portion 2123-1 b. The first terminalportion 2123-1 a may be electrically connected to the third caseterminal 2100-1 c by bolt-coupling. Therefore, a hole for bolt-couplingmay be formed on the first terminal portion 2123-1 a. And the secondterminal portion 2123-1 b may be electrically connected to the fourthcase terminal 2110-1 d by bolt-coupling. Therefore, a hole forbolt-coupling may be formed on the second terminal portion 2123-1 b. Thethird case terminal 2110-1 c and the fourth case terminal 2100-1 c maybe electrically connected to a diode module (not shown). Accordingly,the secondary coil 2122-1 can be electrically connected to the diodemodule through the first terminal 2123-1.

The second terminal 2124-1 may be extended from the secondary coil2122-1. The second terminal 2124-1 may be a member for electricallyconnecting the secondary coil 2122-1 and the inductor coil 2131-1. Thesecond terminal 2124-1 may be a plate-shaped conducting member. Thesecond terminal 2124-1 may be a shape extended from the above towardsthe lower side (vertical direction), and then extended in the horizontaldirection. One end of the second terminal 2124-1 may be curved or bentand extended in the vertical direction at the end portion of thesecondary coil 2122-1. The middle portion of the second terminal 2124-1may be a shape downwardly extended. The other end of the second terminal2124-1 may be in the shape of a plate bent or curved in a horizontaldirection at the middle portion of the second terminal 2124-1. A thirdterminal portion 2124-1 a may be formed at the other end of the secondterminal 2124-1. The third terminal portion 2124-1 a may be electricallyconnected to the seventh terminal portion 2133-1 a by bolt-coupling. Thethird terminal portion 2124-1 a may be formed with a hole forbolt-coupling. Accordingly, the second terminal 2124-1 and the fifthterminal 2133-1 can be electrically connected to each other. Eventually,the secondary coil 2122-1 and the inductor coil 2131-1 are electricallyconnected to each other. According to the above description, the secondterminal 2124-1 may comprise at least one of a bent portion and a curvedportion. In this case, the bent or curved angle of the bent portion orthe curved portion may be right angled.

The tertiary coil 2122-2 may be disposed apart from the primary coil2121-1. The tertiary coil 2122-2 may be positioned below the primarycoil 2121-1. The tertiary coil 2122-2 can electromagnetically interactwith the primary coil 2121-1. In the tertiary coil 2122-2, a current isinduced by the current of the primary coil 212-11 so that an inducedcurrent may be generated. The induced current generated in the tertiarycoil 2122-2 may be a current that is boosted or lowered by the currentflowing through the primary coil 2121.

The tertiary coil 2122-2 may have the shape of an open ring-type platecomprising an upper surface and a lower surface. The initial portion(one end) of the tertiary coil 2122-2 may be a shape extended from thethird terminal 2123-2. The end portion (other end) of the tertiary coil2122-2 may be connected to the fourth terminal 2124-2. That is, one endof the tertiary coil 2122-2 may be electrically connected to the fourthterminal 2123-2, and the other end of the tertiary coil 2122-2 may beelectrically connected to the third terminal 2124-2. The tertiary coil2122-2 and the third and fourth terminals 2123-2 and 2124-2 may beintegrally formed. However, the shape of the tertiary coil 2122-2 is notlimited to the above described ring-type. For example, the tertiary coil2122-2 may be disposed in a three-dimensional spiral shape, spaced apartfrom the primary coil 2121-1 in a vertical or horizontal direction.Further, the tertiary coil 2122-2 may be a three-dimensional spiralshape interleaving with the primary coil 2121-1 while being spaced apartfrom each other. In this case, the primary coil and the tertiary coil2121-1 and 2122-2 may be formed into one double-layeredthree-dimensional spiral.

The third terminal 2123-2 may be a member for electrically connectingthe tertiary coil 2122-2 to the diode module. The third terminal 2123-2may be a plate-shaped conducting member. The third terminal 2123-2 maybe a shape extending horizontally at one end (initial portion) of thetertiary coil 2122-2. The other end of the third terminal 2123-2 can bedivided into a fourth and a fifth terminal portions 2123-2 a and 2123-2b which will be described later.

One end of the third terminal 2123-2 may be electrically connected tothe initial portion of the tertiary coil 2122-2. The other end of thethird terminal 2123-2 can be divided into a fourth terminal portion2123-2 a and a fifth terminal portion 2123-2 b. The fourth terminalportion 2123-2 a and the fifth terminal portion 2123-2 b may beelectrically connected to the diode module through bolt-coupling.Accordingly, the fourth terminal portion 2123-1 a and the fifth terminalportion 2123-2 b may be formed with holes for bolt-coupling.Accordingly, the tertiary coil 2122-2 may be electrically connected tothe diode module through the third terminal 2123-2.

The fourth terminal 2124-2 may be extended from the tertiary winding2122-2. The fourth terminal 2124-2 may be a member for electricallyconnecting the tertiary coil 2122-2 and the inductor coil 2131-1. Thefourth terminal 2124-2 may be a plate-shaped conducting member. Thefourth terminal 2124-2 may be a shape extending horizontally at theother end of the tertiary coil 2122-2. One end of the fourth terminal2124-2 may be located at the end portion of the tertiary coil 2122-2. Asixth terminal portion 2124-2 a may be formed at the other end of thefourth terminal 2124-2. The sixth terminal portion 2124-2 a may beelectrically connected to the seventh terminal portion 2133-1 a throughbolt-coupling. In this case, the third terminal portion 2124-1 a, thesixth terminal portion 2124-2 a, and the seventh terminal portion 2133-1a may be overlappingly positioned in the vertical direction. The sixthterminal portion 2124-2 a may be formed with a hole for bolt-coupling.Accordingly, the fourth terminal 2124-2 and the fifth terminal 2133-1can be electrically connected, and finally, the tertiary coil 2122-2 andthe inductor coil 2131-1 may be electrically connected to each other.

The inductor coil 2131-1 can be supplied with the converted current fromthe secondary coil 2122-1 and the tertiary coil 2122-2. The inductorcoil 2131-1 can rectify the converted current. The inductor coil 2131-1may be connected to the external terminal 2150 to supply a rectifiedcurrent.

The inductor coil 2131-1 may have a shape of a plate comprising an uppersurface and a lower surface grown as a three-dimensional spiral. Thatis, the inductor coil 2131-1 may be in the form of a three-dimensionalspiral, and the initial portion (lower portion) of the spiral growth ofthe inductor coil 2131-1 may be extended from the fifth terminal 2133-1.The sixth terminal 2132-1 may be connected to the end portion (upperportion) of the spiral growth of the inductor coil 2131-1. The bus bar2140-1 may extend from the sixth terminal 2132-1. The inductor coil2131-1, the fifth terminal 2133-1, the sixth terminal 2132-1, and thebus bar 2140-1 may be integrally formed.

The seventh terminal portion 2133-1 a may be formed at one end of thefifth terminal 2133-1. As described above, the seventh terminal portion2133-1 a may be electrically connected to the third terminal portion2124-1 a through bolt-coupling. In addition, the seventh terminalportion 2133-1 a may be electrically connected to the sixth terminalportion 2124-2 a through bolt-coupling. Therefore, the inductor coil2131-1 may be electrically connected to the secondary coil 2122-1 andthe tertiary coil 2122-2. The induced current generated in the secondarycoil 2122-1 and the tertiary coil 2122-2 can be rectified in theinductor coil 2131-2. The other end of the fifth terminal 2133-1 may beextended in the horizontal direction (direction in which the inductorcoil is positioned) at one end of the fifth terminal 2133-1, and may beconnected to the initial portion of the spiral growth of the inductorcoil 2131-2.

One end of the sixth terminal 2132-1 may be connected to the end portionof the spiral growth of the inductor coil 2131-2. The other end of thesixth terminal 2132-1 may be connected to one end of the bus bar 2140-1.The other end of the bus bar 2140-1 may be electrically connected to anexternal terminal 2150. An eighth terminal portion 2140-1 a may beformed at the other end of the bus bar 2140-1 to electrically connect tothe external terminal 2150. The eighth terminal portion 2140-1 a may beformed with a bolt-coupling hole for fixing and electrical connection.The inductor coil 2131-2 may be electrically connected to the externalterminal 2150 through the bus bar 2140-1. As a result, an inductioncurrent generated in the secondary coil 2122-1 and the tertiary coil2122-2 are rectified in the inductor coil 2131-2, and then, may betransmitted to an external electronic device through the bus bar 2140-1.

Third Embodiment

Hereinafter, the DC-DC converter 3001 of the third embodiment will bedescribed with reference to the drawings. FIG. 16 is a perspective viewillustrating the DC-DC converter of the third embodiment with the firstcover removed; FIG. 17 is a cut-away perspective view illustrating theDC-DC converter of the third embodiment; FIG. 18 is a cross sectionalconceptual view illustrating a main board, an auxiliary board and acooling plate of the DC-DC converter of the third embodiment; and FIG.19 is a conceptual diagram illustrating a signal leg of the DC-DCconverter of the third embodiment.

A DC-DC converter 3001 of the third embodiment may be a DC-DC converterused in a vehicle. For example, the DC-DC converter 1000 may play therole of receiving an electric current from an external power supplydevice (such as a lithium ion battery), boosting or lowering a voltage,supplying the voltage to an external electronic device (such as amotor), and thereby controlling the number of revolutions of a motor andthe like. As illustrated in FIG. 17 , the DC-DC converter 3001 maycomprise a housing 3010, a first board 3020, a second board 3030, aconnecting member 3040, a coil unit 3050, and a bus bar 3060. DC-DCconverter 3001 may be referred to as an “electronic component assembly.”In this case, auxiliary configuration such as the coil unit 3050 and thebus bar 3060 may be omitted. In this case, the scope of rights of“electronic component assembly” of the third embodiment may be extendedto various electronic component assemblies as well as the DC-DCconverter 3001. Further, the first board 3020 is a board provided forcooling a device having a high heating value and may be referred to asan “auxiliary board.” Since the first board 3020 has a configurationcompletely different from that of a general board (the cooling plateplays the role of a base of a general board), the name of the board maybe omitted. The second board 3030 may be referred to as “main board” asa board provided to cool a device having a low heating value. When thedesignation of the first board 3020 is omitted, the second board 3030may be referred to as a “board.”

Hereinafter, the housing 3010 will be described with reference to FIGS.16 and 17 . Housing 3010 is an exterior member of DC-DC converter 3001and may be in the form of a hollow block. The housing 3010 may comprisesa main body 3011, a cooling plate 3012, a first cover 3013, a secondcover 3014, an inlet 3015, an outlet 3016, a cooling flow path guide3017, a cooling flow path 3018 and a heat radiating fin 3019. The insideof the housing 3010 can be divided into a first area 3002 located at thelower portion by the cooling plate 3012 and a second area 3003 locatedat the upper portion. The first region 3002 may be a cooling portionthrough which the cooling fluid flows, and the second region 3003 may bean electronic component portion where electronic components aredisposed. The cooling plate 3012, the first cover 3013, the second cover3014, the inlet 3015 and the outlet 3016 of the housing 3010, thecooling flow path guide 3017, the cooling flow path 3018, and the heatradiating fin 3019 may be integrally formed. The material of the housing3010 may be a metal (for example, aluminum).

The main body 3011 may be formed by a side surface, and may have ahollow shape wherein a lower end portion and an upper end portionthereof are open. The first cover 3013 may be disposed at the lower endportion of the main body 3011. In this case, the first cover 3013 cancover and close the opening of the lower end portion of the main body3011. A second cover 3014 may be disposed on the upper end portion ofthe main body 3011. In this case, the second cover 3013 can cover andclose the opening of the upper end portion of the main body 3011. As aresult, the inner space of the housing 3010 can be formed by the mainbody 3011 and the first and the second covers 3012 and 3013.Furthermore, a cooling plate 3012 may be disposed in the interior of themain body 3011 in the form of a horizontal partition. That is, thecooling plate 3012 may be formed over the entire surface of thehorizontal cross section inside the main body 3011. The cooling plate3012 can divide or separate the inside of the main body 3011 into afirst region 3002 and a second region 3003. In this case, the firstregion 3002 and the second region 3003 may be the separate regionsisolated from each other. The first region 3002 may be disposed belowthe cooling plate 3012 and the second region 3003 may be disposed abovethe cooling plate 3012.

An inlet 3015 for introducing the cooling fluid and an outlet 3016 fordischarging the cooling fluid that has flowed along the first region3002 are formed in a portion corresponding to the first region 3002 onthe side surface of the main body 3011.

The first region 3002 can perform a cooling function in a region wherethe cooling fluid flows. A cooling flow path guide 3017 can be disposedon the lower side surface of the cooling plate 3012. In this case, thecooling flow path guide 3017 can have various shapes, and the coolingflow path 3018 can be formed by the cooling flow path guide 3017. Aplurality of heat radiating fins 3019 may be formed in the cooling flowpath 3018 to increase the cooling efficiency. In this case, theplurality of heat radiating fins 3019 may be in the form of protrusionsdownwardly extending from the lower surface of the cooling plate 3012.

The second region 3003 disposed with the electronic components canperform an electronic control function. For this, a first board 3020, asecond board 3030, a connecting member 3040, a coil unit 3050, and a busbar 3060 may be disposed in the second region 3003.

Hereinafter, the first board 3020 will be described with reference toFIG. 18 . The first board 3020 may be a metal printed circuit board(MPCB) having a high heating value. The first board 3020 can be referredto as an “auxiliary board” as a board for mounting a device having ahigh heating value. That is, the device mounted on the first board 3020has a higher heating value than the device mounted on the second board3030, which will be described later. An element mounted on the firstboard 3020 may also be referred to as an “active element.” Here, the“active element” may be an element capable of generating electricenergy. For example, a transistor and an IC controller may correspond tothis.

The first board 3020 may be disposed on the upper surface of the coolingplate 3012. In this case, the lower surface of the first board 3020 cancontact the upper surface of the cooling plate 3012. As a result, thecooling efficiency of the first board 3020 may be higher than that ofthe second board 3030, which will be described later. Since the lowersurface of the first board 3020 is in direct contact with the coolingplate 3012, the element can be mounted only on the upper surface of thefirst board 3020. The first board 3020 may be downwardly spaced apartfrom the second board 3030. That is, the first board 3020 may be stackedwith the second board 3030 spaced apart from each other. As a result, inthe third embodiment, the device mounting rate can be increased in thesame space. The area of the first board 3020 may be smaller than thearea of the second board 3030. The first board 3020 may be electricallyconnected to the second board 3030. The first board 3020 may beelectrically connected to the second board 3030 by a connecting member3040.

The first board 3020 may comprise an adhesive layer 3021, a metal layer3022, an insulating layer 3023, and a pattern layer 3024. The firstboard 3020 may be a shape wherein an adhesive layer 3021, a metal layer3022, an insulating layer 3023, and a pattern layer 3024 aresequentially stacked. The first board 3020 may be configured to beconsisted of only the adhesive layer 3021, the metal layer 3022, theinsulating layer 3023, and the pattern layer 3024.

The adhesive layer 3021 which is a thermally conductive adhesive may bedisposed on the cooling plate 3012. In this case, the adhesive layer3021 can be directly coated on the upper surface of the cooling plate3012. That is, the adhesive layer 3021 can adhere to the upper surfaceof the cooling plate 3012. For example, the adhesive layer 3021 may be athermal grease having a high thermal conductivity. As a result, it ispossible to efficiently cool the heat generated in the element having ahigh heating value to be mounted on the first board 3020. Further, theadhesive layer 3021 can perform the function of coupling the metal layer3022 and the cooling plate 3012.

The metal layer 3022 may be disposed on the adhesive layer 3021. Thatis, the metal layer 3022 may be disposed on the adhesive layer 3021. Themetal layer 3022 may be in the form of a metal plate. The lower surfaceof the metal layer 3022 can be bonded with the upper surface of theadhesive layer 3021. The material of the metal layer 3022 may comprisecopper or aluminum having a high thermal conductivity. The first board3020 with the metal layer 3022 may be referred to as a “metal printedcircuit board.” The cooling efficiency of the first board 3020 can beincreased by the metal layer 3022. In addition, the metal layer 3022 mayserve as a supporting portion in the first board 3020. The insulatinglayer 3023 and the pattern layer 3024 can be supported by the metallayer 3022.

An insulating layer 3023 may be disposed over the metal layer 3022. Thatis, the insulating layer 3023 may be disposed on the metal layer 3022.The insulating layer 3023 may be in the form of a plate made of aninsulating material. The insulating layer 3023 may be a layer forforming the pattern layer 3024.

The pattern layer 3024 may be disposed on the insulating layer 3023. Thepattern layer 3024 may be coated on the insulating layer 3023. Thepattern layer 3024 may be a layer forming a circuit of the first board3020. Thus, the pattern layer 3024 can be various circuit patterns thatare electrically conductive materials. An “active element” may bedisposed in the pattern layer 3024. In this case, the “active element”may comprise an upper surface and a lower surface. The lower surface ofthe “active element” can be soldered to the pattern layer 3024.Therefore, the lower surface of the “active element” can face thecooling plate 3012. The “active element” may be electrically connectedto the pattern layer 3024 by surface mount technology (SMT). Forexample, the “active element” may be electrically connected to thepattern layer 3024 by a plurality of wires.

As described above, the first board 3020 is completely different from ageneral board in that the first board 3020 is composed of materialscoated directly on the cooling plate 3012 with the cooling plate 3012 asa base. Thus, the name of the first board 3020 may be omitted. In thiscase, the first board 3020 may be referred to as an “adhesive layer3021, metal layer 3022, insulating layer 3023, and pattern layer 3024.”

Hereinafter, the second board 3030 will be described with reference toFIG. 18 . The second board 3030 may be a printed circuit board (PCB).The second board 3030 as a board for mounting a device having a lowheating value may be referred to as a “main board.” That is, the devicemounted on the second board 3030 has a lower heating value than thedevice mounted on the first board 3020. The element mounted on thesecond board 3030 may also be referred to as a “passive element.” Here,the “passive device” may be an element that transmits or absorbselectrical energy but does not have an active function, such asconversion of electrical energy.

The second board 3030 may be upwardly spaced apart from the coolingplate 3012. To this end, a member (not shown) for supporting the secondboard 3030 may be disposed on the inner side surface of the secondregion 3003 of the main body 3011. The first board 3020 may be disposedbetween the second board 3030 and the cooling plate 3012. That is, thesecond board 3030 and the first board 3020 may be overlappingly spacedapart from each other. As a result, the cooling efficiency of the secondboard 3030 may be lower than that of the first board 3020. That is, thesecond board 3030 may be stacked spaced apart from the first board 3020.In this case, the area of the second board 3030 may be larger than thearea of the first board 3020. The second board 3030 may be electricallyconnected to the first board 3020. The second board 3030 may beelectrically connected to the first board 3020 by a connecting member3040. The second board 3030 may be disposed spaced apart from the coilunit 3050 which will be described later. In this case, the coil unit3050 can penetrate the first board 3020. Since the coil unit 3050 issupported on the cooling plate 3012 and the first board 3020 is upwardlydisposed spaced apart from the cooling plate 3012, a hole may be formedin the first board 3020 at the portion where the first board 3020 andthe coil unit 3050 are overlapped with each other so that the coil unit3050 can penetrate therethrough. (Refer to FIG. 16 )

The connecting member 3040 can electrically connect the first board 3020and the second board 3030. The connecting member 3040 may be a couplingmember made by a press-fit method. Also, the connecting member 3040 maybe a signal leg. The connecting member 3040 may be a flexible printedcircuit board (FPCB). That is, the connecting member 3040 can be invarious forms. Hereinafter, the case wherein the connecting member 3040is a signal leg will be described with reference to FIG. 20 .

As illustrated in FIG. 19 (a), the connecting member 3040 may comprise afirst conducting member 3041 and a second conducting member 3042 whichis electrically connected to the second board 3030 by being bent orcurved at the first conducting member 3041. In this case, the firstconducting member 3041 may be a pattern of the pattern layer 3024. Thesecond conducting member 3042 may upwardly extend from the firstconducting member 3041 to be electrically connected to the second board3030. In this case, the upper end of the second conducting member 3042can be coupled to the second board 3030 by soldering, pin bonding or thelike.

As illustrated in FIG. 19 (b), the connecting member 3040 may comprise afirst conducting member 3041 which is electrically connected to thepattern layer 3024, and a second conducting member 3042 which is bent orcurved at the first conducting member 3041 and electrically connected tothe second conducting member 3030. In this case, the lower surface ofthe first conducting member 3041 may be electrically connected to thepattern layer 3024. The lower surface of the first conducting member3041 can be bonded to the pattern layer 3024 by soldering or pin bondingor the like. The second conducting member 3042 may upwardly extend fromthe first conducting member 3041 to be electrically connected to thesecond board 3030. The upper end portion of the second conducting member3042 can be bonded to the second board 3030 by soldering or pin bondingor the like.

As illustrated in FIG. 19 (c), the connection member 3040 may comprise:a first conducting member 3041 having the shape of a plate andelectrically connected to the pattern layer 3024; and a secondconducting member 3042 extended from the center of the first conductingmember 3041 towards the second board 3030. In this case, the lowersurface of the first conducting member 3041 may be electricallyconnected to the pattern layer 3024. The lower surface of the firstconducting member 3041 can be bonded to the pattern layer 3024 bysoldering or pin bonding or the like. The second conducting member 3042may be upwardly extended from the first conducting member 3041 to beelectrically connected to the second board 3030. The upper end of thesecond conducting member 3042 can be bonded to the second board 3030 bysoldering or pin bonding or the like.

As illustrated in FIG. 19 (d), the connecting member 3040 may comprise:a first conducting member 3041 having the shape of a plate with a grooveat the center thereof and forming a portion of the pattern layer 3024;and a second conducting member 3042 formed with a protruding part beingaccommodated in the groove of the first conducting member, and extendedfrom the protruding part toward the second board 3030 and electricallyconnected to the second board 3030. In this case, the first conductingmember 3041 may be a pattern of the pattern layer 3024. A protrudingpart corresponding to the groove of the first conducting member 3041 maybe formed on the lower end portion of the second conducting member 3042and may be soldered thereto. As a result, the second conducting member3042 can be electrically connected to the first conducting member and,at the same time, can be supported by the first conducting member 3041.The second conducting member 3042 may be upwardly extended from thefirst conducting member 3041 to be electrically connected to the secondboard 3030. The upper end of the second conducting member 3042 can bebonded to the second board 3030 by soldering or pin bonding or the like.

As described above, the “active element” is disposed on the first board3020 and the “passive element” is disposed on the second board 3030.However, the third embodiment is not limited to this. The “activeelement” and the “passive element” may be collectively referred to as an“electronic element.” The “electronic element” may be disposed on thefirst board 3020 and the second board 3030 without distinguishingbetween the “active element” and the “passive element.”

Hereinafter, the coil unit 3050 and the bus bar 3060 will be describedwith reference to FIG. 16 . The coil unit 3050 can be supported on thecooling plate 3012. In this case, the lower portion of the coil unit3050 can be bonded with the upper surface of the cooling plate 3012. Inaddition, the coil unit 3050 can be disposed spaced apart from thesecond board 3030. In addition, the coil unit 3050 can be overlappinglydisposed with the second board 3030. In this case, the coil unit 3050can penetrate the second board 3030. The coil unit 3050 may be plural.The coil unit 3050 may be a trans-coil unit or an inductor coil unit.When the coil unit 3050 is the trans-coil unit, the coil unit 3050 canconvert the voltage of the power source supplied from the outside. Whenthe coil unit 3050 is the inductor coil unit, the coil unit 3050 canrectify the converted power. The bus bar 3050 may be electricallyconnected to the coil unit 3050 to output the converted and/or rectifiedpower to the outside.

Hereinafter, a DC-DC converter 1 according to a modified embodiment ofthe third embodiment will be described with reference to the drawings.FIG. 20 is a cross sectional conceptual diagram illustrating a mainboard, an auxiliary board and a cooling plate of a DC-DC converteraccording to the modified embodiment of the third embodiment. Themodified embodiment of the third embodiment has the same technical ideaas that of the third embodiment except for the first board 3020.Hereinafter, description of technical ideas substantially the same asthose of the third embodiment will be omitted.

The first board of the modified embodiment of the third embodiment maycomprise an insulating layer 3023 and a pattern layer 3024. The firstboard may be a shape wherein an insulating layer 3023 and a patternlayer 3024 are sequentially stacked. The first board may be composed ofonly the insulating layer 3023 and the pattern layer 3024.

That is, in the modified embodiment of the third embodiment, theadhesive layer 3021 and the metal layer 3022 may be omitted. Instead,the cooling plate 3012 can perform the function of the metal layer 3022.Therefore, the adhesive layer 3021 for bonding the metal layer 3022 andthe cooling plate 3012 may also be omitted.

More specifically, the insulating layer 3023 of the first board may bedirectly coated on the top surface of the cooling plate 3012. That is,the insulating layer 3023 and the upper surface of the cooling plate3012 can be in contact with each other. In this case, the cooling plate3012 made of a metal material can perform the function of supporting themetal layer 3022 of the third embodiment. That is, the first board ofthe modified embodiment of the third embodiment can achieve the sameeffect as the first board 3020 of the third embodiment. At the sametime, since the adhesive layer 3021 and the metal layer 3022 areremoved, the cooling efficiency can be improved, and it is possible tosolve the problem of ensuring a space in the vertical direction, whichbecomes possible by mounting the element on the lower surface of thesecond board 3030 owing to the size reduction in the vertical direction.

In the above, to have been described as all the components that make upthe embodiments of the present invention may operate in combination, orcombined into one, but the invention is not necessarily limited to theseexamples. That is, if the object in the scope of the present invention,may be that all of the components are selectively operates inconjunction with more than one. In addition, terms such as “inclusiveand”, “is configured” or “have” described above is because, which meansthat unless there is a particular of stated that, the component can beembedded, except for the different components it should not be construedto further comprise other components. All terms, including technical andscientific terms, have the same meaning as commonly understood by one ofordinary skill in the art to which this invention belongs, unlessotherwise defined. Commonly used terms, such as predefined terms, shouldbe interpreted to be consistent with the contextual meanings of therelated art, and are not to be construed as ideal or excessivelyformalistic, unless expressly defined to the contrary.

The above description is only to those described as the technical ideaof the present invention by way of example, those skilled in the artthat various modifications, additions and substitutions will be possiblewithout departing from the essential characteristics of the presentinvention. Accordingly, the disclosed invention embodiments is forillustrative and not intended to limit the technical idea of the presentinvention, not by such an embodiment is the technical scope of thepresent invention is not limited. The scope of protection of theinvention is to be interpreted by the following claims, all spiritswithin a scope equivalent will be construed as included in the scope ofthe present invention.

The invention claimed is:
 1. A DC-DC converter comprising: a housingwith a cooling plate; a cooling passage disposed on one surface of thecooling plate; an insulating layer disposed on an other surface of thecooling plate; a pattern layer disposed on the insulating layer; anelectric device disposed on the pattern layer; and a substrate spacedapart from the cooling plate and electrically connected to the patternlayer.
 2. The DC-DC converter according to claim 1, wherein the electricdevice includes an upper surface and a lower surface, and wherein thelower surface of the electric device is soldered to the pattern layer toface the cooling plate.
 3. The DC-DC converter according to claim 1,wherein the cooling plate is integrally formed with the housing.
 4. TheDC-DC converter according to claim 1, wherein a plurality of heatdissipation fins are formed on one surface of the cooling plate, and theplurality of heat dissipation fins have a protrusion shape extending toone side of the cooling plate.
 5. The DC-DC converter according to claim1, comprising: a first substrate disposed on the upper surface of thecooling plate; and a second substrate disposed to be spaced apart fromthe cooling plate on the upper side.
 6. The DC-DC converter according toclaim 5, wherein the first substrate and the second substrate areelectrically connected to each other by soldering a signal bridge or bya press-fit method.
 7. The DC-DC converter according to claim 6, whereinthe signal bridge includes: a first conductive member forming a part ofthe pattern layer; and a second conductive member that is curved or bentin the first conductive member and is electrically connected to thesubstrate.
 8. The DC-DC converter according to claim 6, wherein thesignal bridge includes: a first conductive member electrically connectedto the pattern layer; and a second conductive member that is curved orbent in the first conductive member and is electrically connected to thesubstrate.
 9. The DC-DC converter according to claim 6, wherein thesignal bridge includes: a first conductive member electrically connectedto the pattern layer and having a plate shape; and a second conductivemember extending from the center of the first conductive member towardthe second substrate and electrically connected to the substrate. 10.The DC-DC converter according to claim 6, wherein the signal bridgeincludes: a first conductive member forming a part of the pattern layerand having a plate shape and a groove formed in the center; and a secondconductive member having a protrusion accommodated in the groove of thefirst conductive member and extending from the protrusion toward thesubstrate to be electrically connected to the substrate.
 11. The DC-DCconverter according to claim 1, wherein one end and an other end of thehousing are open, and wherein the housing includes a first covercovering an opening of the one end and a second cover covering anopening of the other end.
 12. The DC-DC converter according to claim 1,wherein the insulating layer is coated on the other surface of thecooling plate.
 13. A DC-DC converter comprising: a housing comprising afirst area in which a flow path of a cooling fluid is formed and asecond area separated from the first area in which electronic componentsare disposed and a cooling plate disposed between the first and secondareas; a main board spaced apart from the cooling plate and disposed inthe second area; an insulating layer disposed on the cooling plate; apattern layer disposed on the insulating layer; and an electric devicedisposed on the pattern layer.